O-470 Engine Mount

[rv8bldr]

Hey everyone

I have a line on a run-out O-470K from a C-180. The price seems reasonable, and having the run-out engine in the shop would allow me to use it to manufacture the engine mount for it before sending it off for overhaul. However, I can't seem to find any design information or drawings on the O-470 engine mounts on the interwebs :-) Have any scratch builders out there had to manufacture their own O-470 mounts or is everyone using ones from Mark ? I would do that, but I know at least one of my firewall engine mount bushings is welded in a tiny bit crooked so there would be no way to get a bolt in. And there are no guarantees that the rest of the bushings are close enough to the plans specified positions to ensure the pre-made mount would fit.

Any design info and/or drawings would be gratefully accepted :-)

Cheers all

[whee]

I want to say this carefully; Bob and Mark put significant effort into designing the O470 mount because it wasn't easy to do. Can't really ask them to give away all that effort for free. If I were you I'd just order the mount unpainted from Mark and if something needed to be tweaked it would be easy to do.

However, if you are set on building your own then look at my build thread on backcountrypilot.org and on page 13 you will see a pic of the mount I built for the TCM io360, Mark M's IO520 mount and a O470 mount for a Stinson. If I were building a mount for a BH I'd model it after the Stinson mount.

Hope that helps.

[rv8bldr]

Yup, that is probably the smart thing to do. I would just hate pay that much for the mount (at today's exchange rate it is about $1,250 CDN) and then inadvertently bugger it up :-) I wasn't looking for design specifics on Mark and Bob's mount; that design is theirs and I would never swipe for my own use. I was more looking for what enterprising builders had come up with on their own.

That all being said, if I were to buy this engine (not decided yet), my plan was to send Mark an email and ask him about doing just what you suggest. I have bought a LOT of parts from Mark for my project, that's why I call it a "scratch'(sh) build" .....

Thanks a lot for your input. I appreciate it.

[whee]

Gotcha. Only 470 powered BHs I know of are Ernie Green's in Florida and another one in Idaho. I'm pretty sure Ernie built his mount. He is a nice enough guy that you could probly call and talk to him about it. The one in Idaho has a IO470 on it and the mount is a modified C180 mount. The Cessna has a much taller firewall so their mounts have to be fairly heavily modified.

The US to CDN exchange rate is great for us and bad for you right now...good time for me to order a bunch of jet boat parts😀

[Mark Moyle]

I started with Avipro's mount. Couldn't find the right motor mount legs to adapt my permold case. Cut up Avipro's mount and used the small parts. To set my motor position I made a fixture to attach with spacers to the oil pan where it bolts to the case. Added all thread to the feet to adjust height and angle. Use a rotating laser level to get the thrust line correct. That took quite a bit of time. Then built the mount to fit.
I'm adding two extra upper motor mounts from the IO520C... Haven't got back to it since folding my right gear leg on the Pacer...have been restoring it.


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[rv8bldr]

Thanks a lot for the photos, Mark. Those are excellent.

As it turns out, the engine I was interested in was removed from a C180 in 1999! If it had been sitting in a hangar in Arizona all that time, that would be one thing. However, it was sitting around in a hangar in Sioux Lookout, northern Ontario. There are all kinds of scary humidity issues there so I took a pass on the engine.

I'll keep looking for now. Although I would like a Lycoming 540, the Continental 470 will remain a possibility if the right one comes along....

[Battson]

Good decision.

[Hans van der Voort]

I don't spend a lot of time on forums, so I am a little late responding.
But I am using also a O 470 K from a C 180. just like you I got an engine that was at max. hours, got the engine mount with it.
I modified the engine mount to fit the Bearhawk. The Bearhawk fire wall is not as tall as a C 180 and this compromised the mount somewhat. I beefed it up with using thicker wall tubing.
And added a Top mount and support in addition. utilizing the 5th. firewall bolt hole on the Bearhawk, see pictures.
I am in the finishing stages of the build process, hope to have ignition system installed this weekend. then it is on to dry testing all systems.

[whee]

Hans, That mount looks great. Looks very similar to my IO360 mount that I based off a Cessna 172xp mount. That top mount concerns me only because where it attaches to the top case bolts. I hope it doesn't cause the case to crack.

[Hans van der Voort]

The Top mount is not under load and only mend as a "safety strap".
It has its own vibration dampeners to mitigate any vibration stress.

[mike 427]

I am flying a IO-470L and made my mount from a cessna motor mount from a 185. I had to add some gussets and thicker tube as well.Having your motor there will help as you can hang it in place and fit it as required.I bought it salvaged.

[Glenn Patterson]

If the engine was removed & stored properly there should not be huge issues. Sitting that long would require a rebuild or a refresh of some description.

We bought one of two IO-360's that were taken off a Cessna 337 in Dryden ON which is an hour away from Sioux Lookout. The mechanics pulled a cylinder so we could take a look inside. The engines had been stored inside for a year or more & were oiled for storage. The rear engine was accidentally opened first as they thought it was the front engine. It had 1400 hrs & had a couple rust blemishes but nothing serious. The humidity here is like the Prairies and is normally very reasonable to dry in spite of lakes everywhere. Today the humidity is higher than normal as it has rained a lot recently and it hit the 90's today. High humidity is not the norm. There is no better place on earth in the summer. We are out numbered 5:1 by non residents in the area for the fishing.

We took the engine & stuffed it in a plywood box lined with plastic, laid a gallon of silica gel in stockings around the engine, laid plastic over and screwed the lid down. The engine sat about 3 years and came out as clean as it did when it was put in the box.

Winters are cold and humidity in local shops are very low as cold air is dry & when heated becomes extremely dry. When we paint in the winter it is really quick between coats with the waterborne paint as the humidity is around 20% or less depending on how cold it is. The water almost flashes out of the paint. We built a large office building for a new pulpmill and at -40F the air was at 15% which is dryer than the Sahara. A steam injector was added into the HVAC to get the humidity to a healthy level.

If the price was really good then there are a couple of maintenance shops where one may get an aircraft mechanic to go from one over to the other shop or to an owner to take a look for you to see if it is a viable engine. It only took the mechanic a few minutes to pull the cylinders to take a peak in the 360's. Sioux Lookout is alive with Cessna 180's series & it may be possible to get a mount cheap.

We used the rear bed mount off the Cessna 337 that we got with the engine for $100 & modified it to fit the BH. I asked Bob Barrows if he would recommend the support tube sizes. I faxed Bob a picture of a similar IO-360 mount used on a South American BH and he marked up the tube sizes then faxed it back a couple days later. If you have a mount then it would not be a huge effort to modify the mount to re-purpose it for a Bearhawk. We had a bare engine block that we used for aligning and fabbing up the modifications. An empty block makes life easy for alignments.


Glenn

[Spokes]

Hi Whee

I googled cont. O 470 engine mounting and found this forum. I am in South Africa.
We are restoring a SAAB Safire with a Conti TSIO 360 engine. The motor were trashed in a hard landing. Does a Conti o 470 use the same engine mount?

I would like to get away from the turbo especially the GB motor. Looking for a IO 360 and can get a very good O 470.